Sensor nodes have been used in the state of being stored in sensor cases from the viewpoint of resistance to environments and prevention of malfunction by incorrect manipulation. Examples of operations for managing sensor nodes included in observation systems include operations in which direct manipulations are more convenient, such as on/off manipulations of the switches of arranged sensor nodes. Thus, access to electronic instruments included in the sensor nodes stored in the sensor cases has been problematic.
The operations have been executed by disposing switches in locations insusceptible to environments in the sensor cases, or by disposing switches with covers. However, measures with hardware are not ultimate solutions to the problems because of reducing environmental resistance and of causing a problem that the costs of sensor nodes are increased.
In addition, physical exchange operations have been needed by drains on the batteries of sensor nodes. There has been a problem that in an operation for transferring logic settings on an exchanged old sensor node to a new sensor node for which the exchange is performed, the correspondence relationships between IDs physically corresponding to the old and new sensor nodes and logical IDs identifying logical positions in a system may be set, thereby causing many errors.